1. Field of the Invention
This invention relates to a composition which is useful in the art of metal compacting, specifically for use with iron base alloy powder compacts consisting of iron powder and lubricant; iron powder, graphite and lubricant; iron powder, copper powder, graphite, and lubricant; and low alloy iron powders blended similarly. Such powder compacts can be infiltrated with typically copper or a copper base alloy in order to minimize compact porosity and/or modify the mechanical properties obtained in the standard compacting or sintering operations. While the process of infiltrating iron powder compacts is well established, the copper base alloys and alloy/mixtures employed in the infiltration process are in a constant state of change, each powder manufacturer seeking an idealized, trouble-free, high yield system.
2. Disclosure Statement
Various infiltrant compositions and processes for using infiltrants are known for impregnating iron and iron base alloy powder compacts, such as are disclosed in U.S. Pat. No. 3,652,261, issued Mar. 28, 1972, to Taubenblat. However, manganese and nickel are included as essential alloying components of the infiltrant disclosed by Taubenblat.
Cuthbert discloses in U.S. Pat. No. 3,994,734, issued Nov. 30, 1976, a high density infiltrating paste made from a metal powder blend containing from about 1.8 to 3.4% of preferably carbonyl iron powder, but does not disclose a dry, compactible, form of infiltrant which can be effectively used without the addition of a liquid vehicle. A copper base alloy containing a minor proportion of aluminum is disclosed by Hechinger in U.S. Pat. No. 3,146,095, issued Aug. 25, 1964.
Fisher discloses in U.S. Pat. No. 3,619,170, issued Nov. 9, 1971, a copper based infiltrating powder including iron, a refractory material parting agent, and a small amount of an iron-chromium alloy as a release agent. Michael in U.S. Pat. No. 3,307,924, issued Mar. 8, 1969, also discloses a powder infiltrant composition comprising copper, iron, and a refractory parting agent. Both Fisher and Michael do not disclose the use of carbonyl iron.
Other copper based infiltrant compositions are disclosed in U.S. Pat. Nos. 4,130,422, issued Dec. 19, 1978, to Wang et al; 3,829,295, issued Aug. 13, 1974, to Farmer et al. Other patents bearing a relation to the field of the invention include the following:
U.S. Pat. No. 3,120,436--Feb. 4, 1964--Harrison PA1 U.S. Pat. No. 3,623,630--Nov. 30, 1971--Rode PA1 U.S. Pat. No. 3,706,550--Dec. 19, 1972--Umehara et al. PA1 U.S. Pat. No. 3,838,982--Oct. 1, 1974--Sanderow et al. PA1 U.S. Pat. No. 4,011,077--Mar. 9, 1977--Kaufman.